基于自适应阈值的脉冲抑制迭代算法研究

Research on Pulse Suppression Iterative Algorithm Based on Adaptive Threshold

电力线信道中存在的脉冲噪声是信号衰减的主要因素,通常采用非线性消隐的CISA迭代算法来消除脉冲噪声,抑制脉冲干扰,但固定阈值的设定并不精确,使得有效信号被消隐处理。为进一步提升降噪性能,提出了一种基于自适应阈值脉冲抑制迭代算法(OISA迭代算法),该算法引入了CE卷积编码算法和VD译码算法来提高噪声估计性能,并采用自适应阈值的方法进行更加精确的消隐处理。仿真实验表明,OISA迭代算法在OFDM系统的性能上比CISA迭代算法有所提升。

The impulse noise in power line channel is the main factor of signal attenuation.The CISA iterative algorithm of non-linear blanking is usually used to eliminate the impulse noise and suppress impulse interference.However,the setting of fixed threshold value is not precise so that effective signals suffer blanking processing.In order to further enhance the performance of noise reduction,an adaptive iterative algorithm based on adaptive threshold pulse suppression（OISA iterative algorithm）is proposed in this paper.The CE convolutional coding algorithm and VD decoding algorithm are introduced in this algorithm to improve the noise estimation performance,and adaptive threshold method is applied to carry out more accurate blanking processing.The simulation experiment shows that the OISA iterative algorithm has better performance than CISA iterative algorithm in OFDM system.